Epoxy based adhesives are used in various applications in automotive, electronics, aerospace and in the general industries. They are increasingly replacing conventional bonding systems such as soldering, welding, rivets, nails, screws and bolts because of the benefits they provide over these systems. Some of these benefits include bonding similar and dissimilar substrates without damaging them, better distribution of stress over wide area, better fatigue resistance and noise and vibration resistance.
A one-component epoxy based adhesive system is preferred over a two-components system because it eliminates the mixing step, the required time to apply it, the cooling during storage and shipping associated with the two-components system.
The present invention relates to latent curing agents and accelerators for epoxy resins including 100% solids epoxy compositions and water-based compositions, especially one-component 100% solids epoxy compositions. “Latent” curing agents are those curatives that in a formulated epoxy system remain inactive under normal ambient conditions but react readily with the epoxy resin at elevated temperatures.
“Accelerators” are those materials that accelerate the reaction between the epoxy resin and the curing agent. “One component” epoxy compositions are typically a blend of an epoxy resin, a curing agent and optionally an accelerator as well as additives and fillers. “100% solids” means the epoxy composition contains no water or organic solvent.